D&D 5E Casting multiple spells with bonus spells and the order they are cast.

[dpkress2]

My understanding is that if you cast a spell as a bonus action you cannot cast another spell unless it is a cantrip with a casting time of 1 action.
This limitation ONLY applies when you cast a spell as a bonus action. So for example, if you are a caster with fighter levels you CAN cast two spells of any level with a casting time of 1 action IF you are using your action surge.

Please correct me if I am wrong with the above statements.

So here is my question....

If it's true that if you cast a spell as a bonus action you cannot cast another spell unless it is a cantrip with a casting time of 1 action, does it follow that if you cast a 1st level or higher spell with a casting time of 1 action BEFORE you use your bonus action, that you cannot use your bonus action to cast a spell with a casting time of 1 bonus action?

...and what if it is a cantrip with a casting time of 1 bonus action?

 

[jaelis]

My understanding is that if you cast a spell as a bonus action you cannot cast another spell unless it is a cantrip with a casting time of 1 action.
This limitation ONLY applies when you cast a spell as a bonus action. So for example, if you are a caster with fighter levels you CAN cast two spells of any level with a casting time of 1 action IF you are using your action surge.

Yep, but note that even with action surge, if you cast a bonus action spell, you're limited to cantrips, though you could cast two cantrips. It also keeps you from casting a reaction spell.

If it's true that if you cast a spell as a bonus action you cannot cast another spell unless it is a cantrip with a casting time of 1 action, does it follow that if you cast a 1st level or higher spell with a casting time of 1 action BEFORE you use your bonus action, that you cannot use your bonus action to cast a spell with a casting time of 1 bonus action?

Yes, that is correct.

...and what if it is a cantrip with a casting time of 1 bonus action?

Are there any? If so, it is still a bonus action spell. If you cast that cantrip, then the only other spell(s) you can cast in that turn are regular action cantrips.

It is kind of a clunky rule. If the weird cases came up often enough to worry about, I would houserule it.

 

[dpkress2]

It also keeps you from casting a reaction spell.

From what I read this isn't true. Most reaction spells don't occur on your turn and ones that do, counterspelling counterspell, for example, are not effected by that limitation. At least that's what I read in this errata....

http://media.wizards.com/2015/downloads/dnd/SA_Compendium_1.0.pdf

Are there any?

Yes: Magic Stone & shillelagh

To rephrase my question because I am a little confused about that last part of your comment...

If you cast a spell of first level or higher that has a casting time of 1 action BEFORE you take your bonus action, can you or can you not cast a cantrip that has a casting time of 1 bonus action (such as Magic stone or Shillelagh) as a bonus action?

 

[guachi]

No. If you use your action to cast a non cantrip spell, the only spell you can cast is a reaction spell.

 

[jaelis]

From what I read this isn't true. Most reaction spells don't occur on your turn and ones that do, counterspelling counterspell, for example, are not effected by that limitation. At least that's what I read in this errata....

http://media.wizards.com/2015/downloads/dnd/SA_Compendium_1.0.pdf

What the Sage Advice says is that, if you cast a reaction spell on your turn, then that doesn't restrict any other spell casting you might do. But that doesn't change the restriction that if you cast a bonus action spell, the only other spells you can cast are regular action cantrips. So you can cast fireball + counterspell, but not healing word + counterspell. Not because of counterspell, but because of healing word.

If that doesn't make sense, which part of the Sage Advice document were you looking at?

Yes: Magic Stone & shillelagh

To rephrase my question because I am a little confused about that last part of your comment...

If you cast a spell of first level or higher that has a casting time of 1 action BEFORE you take your bonus action, can you or can you not cast a cantrip that has a casting time of 1 bonus action (such as Magic stone or Shillelagh) as a bonus action?

You cannot. So if you cast magic missile, you cannot subsequently cast magic stone.

 

[dpkress2]

What the Sage Advice says is that, if you cast a reaction spell on your turn, then that doesn't restrict any other spell casting you might do. But that doesn't change the restriction that if you cast a bonus action spell, the only other spells you can cast are regular action cantrips. So you can cast fireball + counterspell, but not healing word + counterspell. Not because of counterspell, but because of healing word.

If that doesn't make sense, which part of the Sage Advice document were you looking at?

That's what I was looking at. I think it's all cleared up now.

You can counterspell the counterspell as a reaction, even if you have cast a spell as an action, or even two with Action surge.

But you cannot cast a reaction spell on your turn if you have already cast a bonus action spell.

And I apologize but this brings me to hopefully my last question.

If you cast a bonus spell action on your turn does this restriction apply until your next turn? Meaning you cannot cast a reaction spell on someone else's turn, such as Shield?

What about a monster with legendary actions? If a monster casts a bonus spell on their turn, can they not cast 1st level spells for their legendary actions?

 

[jaelis]

If you cast a bonus spell action on your turn does this restriction apply until your next turn? Meaning you cannot cast a reaction spell on someone else's turn, such as Shield?

Nope, the restriction only applies to your actual turn.

What about a monster with legendary actions? If a monster casts a bonus spell on their turn, can they not cast 1st level spells for their legendary actions?

Same, the restriction only applies to that turn.

 

[Ovinomancer]

That's what I was looking at. I think it's all cleared up now.

You can counterspell the counterspell as a reaction, even if you have cast a spell as an action, or even two with Action surge.

But you cannot cast a reaction spell on your turn if you have already cast a bonus action spell.

And I apologize but this brings me to hopefully my last question.

If you cast a bonus spell action on your turn does this restriction apply until your next turn? Meaning you cannot cast a reaction spell on someone else's turn, such as Shield?

What about a monster with legendary actions? If a monster casts a bonus spell on their turn, can they not cast 1st level spells for their legendary actions?

I don't think that's correct. The intent seems to be that casting a reaction spell is completely separate to other events during your turn. I would think that not being able to use your reaction on your turn to cast a spell if you had cast a bonus action spell would have been a big enough caveat to have been called out.

 

[Illithidbix]

It is a strong contested for "rule most likely to be forgotten".

If you cast a spell of first level or higher that has a casting time of 1 action BEFORE you take your bonus action, can you or can you not cast a cantrip that has a casting time of 1 bonus action (such as Magic stone or Shillelagh) as a bonus action?

I think the thing here is to look at your turn as a whole.
If you have done a thing that restricts which actions you can take on your turn (by saying you can't or by saying it requires a certain type of action), then it doesn't matter what order it happens in.

I recall a similar debate about whether using the Shield Master bonus action shove.

 

[jaelis]

I don't think that's correct. The intent seems to be that casting a reaction spell is completely separate to other events during your turn. I would think that not being able to use your reaction on your turn to cast a spell if you had cast a bonus action spell would have been a big enough caveat to have been called out.

It says you can't cast any spells besides std-action cantrips, that seems pretty comprehensive.